1. Field of the Invention
The invention concerns a head coil provided as a radio-frequency antenna for a magnetic resonance apparatus, the head coil being configured to be arranged around the head of a patient to be examined with a magnetic resonance apparatus.
2. Description of the Prior Art
A head coil (also known as a head array antenna) for a magnetic resonance tomography apparatus is known from DE 195 05 062 A1, for example. An arrangement of sub-antennas is located on the generated surface of a support body of the known head coil, wherein the generated surface can represent an inner or outer surface of a hollow cylindrical segment. The known head coil furthermore has an end segment that can be fashioned as a spherical cap, such that the head array antenna approximates a helmet in its shape. Just as on the generated surface, butterfly antennas can be arranged on the end segment. Individual sub-antennas on the generated surface are formed by a loop antenna and a butterfly antenna. In contrast to this, an auxiliary antenna arranged on the end segment is formed as a circularly polarized antenna made up of two butterfly antennas arranged crossed relative to one another. The imaging region should be homogenized via a partial, mutual overlapping of the butterfly antennas.